<!DOCTYPE html>
<html lang="en">

<head>
  <meta charset="UTF-8" />
  <link rel="icon" href="/favicon.ico" />
  <meta name="viewport" content="width=device-width, initial-scale=1.0" />
  <title>Vite App</title>
</head>

<body>
  <div id="app">
    x: {{ x }} <br />
    y: {{ y }}
  </div>
  <script type="module">
    import {
      createApp,
      reactive,
      onMounted,
      onUnmounted,
      toRefs
    } from "./node_modules/vue/dist/vue.esm-browser.js"

    function useMousePosition() {
      // 第一个参数 props
      // 第二个参数 context, attrs, emit, slots
      const position = reactive({
        x: 0,
        y: 0,
      })
      const update = (e) => {
        position.x = e.pageX
        position.y = e.pageY
      }

      onMounted(() => {
        window.addEventListener("mousemove", update)
      })

      onUnmounted(() => {
        window.addEventListener("mousemove", update)
      })
      return toRefs(position)
    }

    const app = createApp({
      setup() {
        const { x, y } = useMousePosition()
        return { x, y }
      }
    })
    console.log(app)
    app.mount("#app")
  </script>
</body>

</html>